90% of the pupils are boys. 70% of the boys and 80% of the girls wear glasses. What percentage of the pupils do not wear glasses?
| Boys |
Girls |
Total |
| 90% |
10% |
100% |
| Wear glasses |
Do not wear |
Wear glasses |
Do not wear |
|
| 63% |
27% |
8% |
2% |
100% |
Number of boys who wear glasses
= 70% x 90%
=
70100 x 90%
= 63%
Number of girls who wear glasses
= 80% x 10%
=
80100 x 10%
= 8%
Percentage of pupils who wear glasses
= 63% + 8%
= 71%
Percentage of pupils who do not wear glasses
= 100% - 71%
= 29%
Answer: 29%
